Biobased plastics can be mechanically recycled just like conventional plastics and biodegradable plastics are not a solution to the plastic soup in the oceans. These are two key findings in the report ‘Biobased and biodegradable plastics – Facts and Figures’, released this week by Wageningen Food & Biobased Research. The report takes stock of scientific knowledge on biobased and biodegradable plastics, and focuses on the plastics used in the packaging industry.

There are many misunderstandings about biodegradable and biobased plastics, some of them quite persistent. As this makes the choice to switch to these materials difficult for companies, Wageningen Food & Biobased Research was commissioned by the Dutch government to carry out an inventory of the current scientific research into these plastics. “Companies and interest groups can state anything,” points out Christiaan Bolck, programme manager for materials at Wageningen Food & Biobased Research. “This report is intended for those who wish to learn the facts. And it shows that the story is often more nuanced than it seems.”

Terminology

The lack of clarity is partly due to terminology. The seemingly simple term ‘bioplastic’, for instance, normally refers to plastics made mostly from plant biomass, but has also been used as a synonym for biodegradable plastic. These are, however, two completely separate characteristics, and the report clearly distinguishes between them.

Facts, myths and nuance

The confusion surrounding biobased and biodegradable plastics is in part also due to assertions that lack nuance. For instance, saying that all plastic is bad for the environment is no more correct than stating that all bioplastics are green and good for the environment.

Such statements are, however, often made by both companies and environmental action groups in the market, and they eventually take on a life of their own. For example, we sometimes hear that the net CO₂ production of bio-based plastics barely differs from that of fossil-fuel plastics as any savings in oil are lost due to the energy consumption of the production process. “However, our report shows that the production of many biobased plastics does result in less net greenhouse gas emissions than traditional plastic,” Bolck says.

Plastic waste

The report also records facts relevant to current debates about plastic packaging waste. For instance, it has been shown that most of the bio-based and biodegradable plastics currently on the market can be mechanically recycled just as easily as ordinary types of plastic, but also that biodegradable plastic is no panacea to the environmental problems caused by littering. Whether – and, especially, how fast – a type of biodegradable plastic is broken down by microorganisms depends largely on the environment in which it ends up. “There are biodegradable plastics that completely break down in the sea within a few months, but seabirds can still choke on a biodegradable plastic bag,” Bolck explains.